arXiv subjects

A. Ghasemi

Publications and source records attributed to A. Ghasemi.

7 recordsLinked to original sources

arXiv2026

AIMBio-Mat: An AI-Native FAIR Platform for Closed-Loop Materials Discovery and Biomedical Translation

Materials discovery and biomedical translation increasingly require models that can reason across composition, processing, structure, biological response, manufacturability, safety, and governance constraints. Existing materials and biomedical data ecosystems are powerful but remain poorly coupled for AI-guided discovery. Here we present AIMBio, a conceptual framework for an AI-native, FAIR, and governance-aware decision layer that links materials provenance, biomedical context, knowledge graphs, uncertainty-aware machine learning, and human-in-the-loop active learning. The framework formulates biomedical-materials discovery as constrained multi-objective optimization under uncertainty and introduces practical requirements for metadata, model documentation, risk-tiered governance, evaluation metrics, and phased implementation. To make the roadmap testable, we add a minimum viable prototype specification and a worked pilot for AI-guided nanomaterials for drug delivery. AIMBio is positioned as exploratory and preclinical discovery infrastructure, not as clinical decision-support software; any clinical or regulated-device use would require separate validation, change control, and regulatory review. The central contribution is a publishable platform blueprint for converting fragmented materials and biomedical records into auditable, experimentally actionable, and translationally responsible discovery workflows.

physics.app-ph↗

arXiv2026

Building a Regional Data-Centric Materials Science Ecosystem for Processing-Rich Materials Innovation in the Great Plains

Data-centric materials science is changing how materials are discovered, optimized, manufactured, and qualified, yet many deployment-limiting materials problems still depend on experimental, processing-rich, device-level, and field-relevant data that are difficult to capture in conventional materials databases. This perspective argues that the Great Plains and adjacent interior research corridor can make a distinctive national contribution by organizing distributed experimental assets into a trusted regional materials-data ecosystem. The proposed model emphasizes FAIR metadata, provenance, persistent sample identifiers, uncertainty-aware modeling, semi-closed-loop workflows, stackable workforce training, and tiered governance for academic, public, controlled-access, and industry-protected data. We identify five coupled barriers -- fragmented data, weak algorithm--laboratory translation, uneven access to cyberinfrastructure and technical staff, workforce gaps at the materials--data interface, and insufficient incentives for sharing and reuse -- and propose a staged roadmap for addressing them. A high-purity germanium pilot illustrates how regional strengths can be converted into reusable datasets, benchmark models, trained personnel, and decision-improving workflows. The broader message is that regional leadership in data-centric materials science will depend less on geographic concentration than on trustworthy data practices, interoperable infrastructure, cross-trained people, and application-driven materials challenges.

cond-mat.mtrl-sci↗

arXiv2018

Synthesis, crystal growth and characterization of the pyrochlore Er2Ti2O7

Pyrochlore erbium titanate samples in the form of powders (with nominal compositions of Er2Ti2+xO7) and bulk single crystals were prepared to elucidate the effect of synthesis and growth conditions on their composition, structure, and transition temperature. All samples were characterized using X-ray diffraction and specific heat measurements. Larger lattice parameters were measured for the Ti-deficient stuffed powders, Er2(Ti2-xErx)O7-δ, while Ti-rich anti-stuffed powders, (Er2-xTix)Ti2O7+δ, showed a decrease in lattice parameter. The lattice parameter for the stoichiometrically synthesized powder, Er2Ti2O7, was measured to be a = 10.07522(9) Å. Single crystals grown by the conventional floating zone (FZ) technique were Ti deficient (stuffed) and darker in color due to oxygen vacancies. Using the traveling solvent floating zone (TSFZ), a high structural quality, transparent and stoichiometric Er2Ti2O7 single crystal was grown at a lower temperature using the TiO2 solvent. Heat capacity measurements of the TSFZ grown Er2Ti2O7 crystal and stoichiometric powder exhibited a very close magnetic transition temperature TC ~1.23K that was suppressed in off-stoichiometric samples, demonstrating correlations between stoichiometry and ground state magnetism in Er2Ti2O7.

cond-mat.mtrl-sci↗

arXiv2016

Spectral/hp Hull: A Degree of Freedom Reducing Discontinuous Spectral Element Method for Conservation Laws with Application to Compressible Fluid Flow

In conventional spectral/finite element methods, the triangulation/quadrilateralization of the domain produces many interior edges which require additional DOF. What if we could directly use the original hull without going to triangulation/quadrilateralization? There are three major difficulties with this type of approach that are addressed: 1- How can a convex hull tessellation be obtained for complex geometries encountered in practical engineering applications? 2- How can basis functions and quadrature points be defined on these hulls? 3- How can this type of grid and corresponding basis functions be used in practice to yield accurate discretization of nonlinear conservation laws? Geometrical approaches to tackle the first challenge are discussed . To solve the second challenge, for the first time in the literature, a closed form relation is proposed to approximate Fekete points (a Nondeterministic Polynomial (NP) problem) on a general convex/concave polyhedral. The approximate points are used to generate basis functions using the SVD of the Vandermonde matrix. The type of basis functions derived include Lagrange basis, orthogonal and orthonormal hull basis and radial basis. It is shown that the hull basis is the best choice to enforce minimum DOF while maintaining a small Lebesgue constant when very high p-refinement is done. The proposed hull basis is rigorously proven to achieve arbitrary order of accuracy by satisfying Weierstrass approximation theorem in $\mathbb{R}^d$. The third challenge is met using a standard Discontinuous Galerkin (DG) and Discontinuous Least-Squares (DLS) spectral hull formulations. The accuracy and stability of the formulation is demonstrated for the linearized acoustics and two-dimensional compressible Euler equations on some benchmark problems including a cylinder, airfoil, vortex convection and compressible vortex shedding from a triangle.

math.NA↗

arXiv2016

One and two spin$-1/2$ particles systems under Lorentz transformations

Lorentz transformation (LT) is used to connect two inertia frames, including the lab and moving frames, and the effect of LT on the states of one spin-1/2 particle system is studied. Moreover, we address the predictions made by Czachor's and the Pauli spin operators about the spin behavior and compare our results with the behavior of system's state under Lorentz transformation. This investigation shows that the predictions made by considering the Pauli spin operator about the spin of system are in better agreement with the system's state in comparison with that of made by considering Czachor's spin operator. In continue, we focus on two-particle pure entangled systems including two spin$-1/2$ particles which moves away from each other. Once again, the behavior of this system's states under Lorentz transformation are investigated. We also point to the behavior of Bell's inequality, as a witness for non-locality, under Lorentz transformation. Our study shows that the Bell operator made by the Pauli operator has better consistency with the behavior of spin state of system under Lorentz transformation compared with the Bell operator made by Czachor's operator. Our approach can be used to study the relation between the various spin operators and the effect of LT on system, which provides the basement to predict the outcome of a Stern-Gerlach type experiment in the relativistic situations.

quant-ph↗

arXiv2015

Thermodynamic analysis of universes with the initial and final de-Sitter eras

Our aim is studying the thermodynamics of cosmological models including initial and final de-Sitter eras. For this propose, bearing Cai-Kim temperature in mind, we investigate the thermodynamic properties of a dark energy candidate with variable energy density, and show that the state parameter of this dark energy candidate should obey the $ω_D\neq-1$ constraint, whiles there is no interaction between the fluids filled the universe, and the universe is not in the de-Sitter eras. Additionally, based on thermal fluctuation theory, we study the possibility of inducing fluctuations to the entropy of the dark energy candidate due to a mutual interaction between the cosmos sectors. Therefore, we find a relation between the thermal fluctuations and the mutual interaction between the cosmos sectors, whiles the dark energy candidate has a varying energy density. We point to models in which a gravitationally induced particle production process leads to change the expansion eras, whiles the corresponding pressure is considered as the cause of current acceleration phase. We study its thermodynamics, and show that such processes may also leave thermal fluctuations into the system. We also find an expression between the thermal fluctuations and the particle production rate. Finally, we use Hayward-Kodama temperature to get a relation for the horizon entropy in models including the gravitationally induced particle production process. Our study shows that the first law of thermodynamics is available on the apparent horizon whiles, the gravitationally induced particle production process, as the dark energy candidate, may add an additional term to the Bekenstein limit of the horizon.

gr-qc↗

arXiv2013

A Progressive Statistical Method for Preconditioning Matrix-Free Solution of High-Order Discretization of Linear Time-Dependent Problems

Preconditioning of a linear system obtained from spectral discretization of time-dependent PDEs often results in a full matrix which is expensive to compute and store specially when the problem size increases. A matrix-free implementation is usually applied to resolve this issue. In this framework, preconditioning is typically challenging since the entries of the matrix are not explicitly available. In this short note, we propose a statistical approach to gradually create a preconditioner matrix by collecting the information obtained from matrix-vector product in the Arnoldi loop of an unpreconditioned Krylov subspace algorithm. The gathered information are then correlated using a multiple regressors estimate where the error is assumed to be normally distributed. This procedure yields a banded diagonal matrix which is then used as a preconditioner in the next iterative solve. This is repeated between iterative solves until a good preconditioner is constructed on fly. This statistically iterative procedure is progressive since the fidelity of the preconditioning matrix improves by adding more data obtained from matrix-vector product during the entire solution procedure. The proposed algorithm is validated for a sample implementation.

math.ST↗